Method and apparatus for controlling power of mobile station

ABSTRACT

A method, including making one or more measurements at a mobile device of path loss for a transmission between said mobile device and a base station in a first frequency band of a plurality of frequency bands in which the mobile device is configured to make transmissions to said base station; receiving at said mobile device path loss estimate information specifying an estimate of the relationship between said path loss for a transmission between said mobile device and said base station in said first frequency band, and path loss for a transmission between said mobile device and said base station in a second frequency band of said plurality of frequency bands; and determining a transmission power for at least one transmission to said base station in said second frequency band on the basis of at least said one or more measurements and said path loss estimate information.

The present invention relates to apparatus for facilitating the use ofspectrum aggregation in uplink transmissions from a mobile station to abase station. In one embodiment, it relates to a technique forfacilitating the use of spectrum aggregation in an orthogonal subcarrieruplink data transmission technique known as Single Carrier-FrequencyDomain Multiple Access (SC-FDMA).

A communication device can be understood as a device provided withappropriate communication and control capabilities for enabling usethereof for communication with others parties. The communication maycomprise, for example, communication of voice, electronic mail (email),text messages, data, multimedia and so on. A communication devicetypically enables a user of the device to receive and transmitcommunication via a communication system and can thus be used foraccessing various service applications.

A communication system is a facility which facilitates the communicationbetween two or more entities such as the communication devices, networkentities and other nodes. A communication system may be provided by oneor more interconnect networks. One or more gateway nodes may be providedfor interconnecting various networks of the system. For example, agateway node is typically provided between an access network and othercommunication networks, for example a core network and/or a datanetwork.

An appropriate access system allows the communication device to accessto the wider communication system. An access to the wider communicationssystem may be provided by means of a fixed line or wirelesscommunication interface, or a combination of these. Communicationsystems providing wireless access typically enable at least somemobility for the users thereof. Examples of these include wirelesscommunications systems where the access is provided by means of anarrangement of cellular access networks. Other examples of wirelessaccess technologies include different wireless local area networks(WLANs) and satellite based communication systems.

A wireless access system typically operates in accordance with awireless standard and/or with a set of specifications which set out whatthe various elements of the system are permitted to do and how thatshould be achieved. For example, the standard or specification maydefine if the user, or more precisely user equipment, is provided with acircuit switched bearer or a packet switched bearer, or both.Communication protocols and/or parameters which should be used for theconnection are also typically defined. For example, the manner in whichcommunication should be implemented between the user equipment and theelements of the networks and their functions and responsibilities aretypically defined by a predefined communication protocol. Such protocolsand or parameters further define the frequency spectrum to be used bywhich part of the communications system, the transmission power to beused etc.

In the cellular systems a network entity in the form of a base stationprovides a node for communication with mobile devices in one or morecells or sectors. It is noted that in certain systems a base station iscalled ‘Node B’. Typically the operation of a base station apparatus andother apparatus of an access system required for the communication iscontrolled by a particular control entity. The control entity istypically interconnected with other control entities of the particularcommunication network. Examples of cellular access systems includeUniversal Terrestrial Radio Access Networks (UTRAN) and GSM (GlobalSystem for Mobile) EDGE (Enhanced Data for GSM Evolution) Radio AccessNetworks (GERAN).

Fragmentation of the radio spectrum for communication systems hasresulted from, for example, the adoption of more spectrally efficienttechnologies, and the failure of old techniques to use frequenciesefficiently. Spectrum aggregation is the collective term for makingeffective use of multiple and simultaneously available spectralfragments (i.e. sections of the radio spectrum that are vacated orotherwise unused/underutilised) for new or alternative services, and isconsidered to represent an evolutionary development in the future useand development of the radio spectrum.

In communication systems the uplink, in other words the communicationpath from the user or user equipment to the access node, which may be aNode B or enhanced Node B (eNB), requires parameters for example poweruse to be controlled. Current up-link power control schemes are based ona fractional path loss compensation methods, where the user equipmentphysical uplink shared channel (and also the control channel)transmission power is adjusted based on measurements from the UEexperienced path loss between the UE and the access node.

However this is problematic in non-contiguous band communication, inother words where spectrum aggregation is carried out, as the integralpath loss is likely to be significantly different and dependent on thespectrum frequency. For example it would be expected that higherfrequencies are likely to experience higher pass losses. A possiblesolution would be to monitor the path loss for each frequency band orspectrum used. However the approach of monitoring all of the uplinkfrequency bands is problematic in that the method would introduce asignificant monitoring and processing burden on the user equipment. Forexample the user equipment may have to receive and monitor frequencybands or spectrum which the user equipment is not currently receivingduring that period and thus consuming more power and or processingcapacity therefore reducing the battery lifetime.

It is an aim of the present invention to efficiently facilitate theexploitation of spectrum aggregation in an uplink transmissiontechnique.

The present invention provides a method, comprising: making one or moremeasurements at a mobile device of path loss for a transmission betweensaid mobile device and a base station in a first frequency band of aplurality of frequency bands in which the mobile device is configured tomake transmissions to said base station; receiving at said mobile devicepath loss estimate information specifying an estimate of therelationship between said path loss for a transmission between saidmobile device and said base station in said first frequency band, andpath loss for a transmission between said mobile device and said basestation in a second frequency band of said plurality of frequency bands;and determining a transmission power for at least one transmission tosaid base station in said second frequency band on the basis of at leastsaid one or more measurements and said path loss estimate information.

The path loss estimate information is preferably received from said basestation as part of radio resource control signalling, or part ofcell-specific system information.

According to a second aspect of the invention there is provided a methodcomprising: sending to a mobile device path loss estimate informationspecifying an estimate of the relationship between path loss for atransmission between said mobile device and a base station in a firstfrequency band of a plurality of frequency bands in which said mobiledevice is configured to make transmissions to said base station, andpath loss for a transmission between said mobile device and said basestation in a second frequency band of said plurality of frequency bands.

The path loss estimate information is sent to said base station as partof radio resource control signalling, or part of cell-specific systeminformation

The first frequency band is preferably specified to be the same for anylink between any mobile device and said base station.

The base station is preferably part of a network of base stations, andsaid first frequency band is preferably specified to be the same for anylink between said mobile device and any of said network of basestations.

The at least one transmission is preferably a multi-carrier transmissionat a series of orthogonal frequencies within said second frequency band.

According to a third aspect of the invention there is providedapparatus, configured to: make one or more measurements at a mobiledevice of path loss for a transmission between said mobile device and abase station in a first frequency band of a plurality of frequency bandsin which the mobile device is configured to make transmissions to saidbase station; receive at said mobile device path loss estimateinformation specifying an estimate of the relationship between said pathloss for a transmission between said mobile device and said base stationin said first frequency band, and path loss for a transmission betweensaid mobile device and said base station in a second frequency band ofsaid plurality of frequency bands; and determine a transmission powerfor at least one transmission to said base station in said secondfrequency band on the basis of at least said one or more measurementsand said path loss estimate information.

The apparatus may be configured to receive said path loss estimateinformation from said base station as part of radio resource controlsignalling, or part of cell-specific system information.

According to a fourth aspect of the invention there is providedapparatus configured to: send to a mobile device path loss estimateinformation specifying an estimate of the relationship between path lossfor a transmission between said mobile device and a base station in afirst frequency band of a plurality of frequency bands in which saidmobile device is configured to make transmissions to said base station,and path loss for a transmission between said mobile device and saidbase station in a second frequency band of said plurality of frequencybands.

The path loss estimate information is preferably sent to said basestation as part of radio resource control signalling, or part ofcell-specific system information

The first frequency band is preferably specified to be the same for anylink between any mobile device and said base station.

The base station is preferably part of a network of base stations, andsaid first frequency band is specified to be the same for any linkbetween said mobile device and any of said network of base stations.

The at least one transmission is preferably a multi-carrier transmissionat a series of orthogonal frequencies within said second frequency band.

A computer program product comprising program code means which whenloaded into a computer controls the computer to preferably perform amethod described above.

According to a fifth aspect of the invention there is providedapparatus, configured to: determine a first frequency band from aplurality of frequency bands for transmission between the apparatus anda further apparatus; measure for the first frequency band a path lossvalue between the further apparatus and the apparatus; determine a pathloss difference value for each of the remainder of the plurality offrequency bands; and determine a transmission power for each of thefrequency bands dependent on the path loss value measured, wherein thetransmission power for the remainder of the plurality of the frequencybands is further dependent on the associated path loss difference value.

According to a sixth aspect of the invention there is providedapparatus, configured to: transmit to at least one further apparatus anindicator identifying a first frequency band from a plurality offrequency bands for transmission between the apparatus and the at leastone further apparatus; and transmit to the at least one furtherapparatus a path loss difference value for each of a remainder of theplurality of frequency bands.

The apparatus is preferably a user equipment and the further apparatusis preferably an access node.

The apparatus is preferably an access node and the further apparatus ispreferably a user equipment.

According to a seventh aspect of the invention there is provided amethod comprising: determining a first frequency band from a pluralityof frequency bands for transmission between an apparatus and a furtherapparatus; measuring for the first frequency band a path loss valuebetween the further apparatus and the apparatus; determining a path lossdifference value for each of the remainder of the plurality of frequencybands; and determining a transmission power for each of the frequencybands dependent on the path loss value measured, wherein thetransmission power for the remainder of the plurality of the frequencybands is further dependent on the associated path loss difference value.

According to an eighth aspect of the invention there is provided amethod comprising: transmitting from an apparatus to at least onefurther apparatus an indicator identifying a first frequency band from aplurality of frequency bands for transmission between the apparatus andthe at least one further apparatus; and transmitting from the apparatusto the at least one further apparatus a path loss difference value foreach of a remainder of the plurality of frequency bands.

A computer program product comprising program code means which whenloaded into a computer controls the computer may perform a method asfeatured above.

An embodiment of the invention is described in detail hereunder, by wayof example only, with reference to the accompanying drawings, in which:

FIG. 1 illustrates a radio network within which embodiments of theinvention may be implemented including a number of cells each served bya respective base station (eNodeB);

FIG. 2 illustrates an apparatus suitable for implementing embodiments ofthe invention;

FIG. 3 illustrates an access node or base station of the radio networkshown in FIG. 1 in further detail;

FIG. 4 illustrates the division of a part of a frequency band into agroup of orthogonal sub-carriers for a SC-FDMA uplink transmission;

FIG. 5 illustrates an example of spectrum fragmentation; and

FIG. 6, shows an example of the operation of an embodiment of theinvention.

In the following certain specific embodiments are explained withreference to communication system standards known as long-term evolution(LTE) an attempt to improve on the communication systems known asUniversal Mobile Telecommunication Systems (UMTS). However it would beappreciated by persons skilled in the art that other embodiments of theinvention may be applied to other communications standards where controlof the uplink communications power transmitted is desired and where theuplink communication is distributed over multiple frequency bands whichare not necessarily contiguous.

FIGS. 1, 2 and 3 show respectively the communication system or network,an apparatus for communication within the network, and an access node ofthe communications network.

FIG. 1 shows a communications system or network comprising a firstaccess node 2 with a first coverage area 101, a second access node 4with a second coverage area 103 and a third access node 105 with a thirdcoverage area. Furthermore FIG. 1 shows an exemplary apparatus 8 whichis configured to communicate with at least one of the access nodes 2, 4,6. These coverage areas may also be known as cellular coverage areas orcells where the access network is a cellular communications network.

FIG. 2 shows a schematic partially sectioned view of an apparatus 8 forexample an user equipment, also known as a mobile device, 8 that may beused for accessing the access nodes and thus the communication systemvia a wireless interface. The user equipment (UE) 8 may be used forvarious tasks such as making and receiving phone calls, for receivingand sending data from and to a data network and for experiencing, forexample, multimedia or other content.

The apparatus 8 may in embodiments of the invention be any devicecapable of at least sending or receiving radio signals. Non-limitingexamples include a mobile station (MS), a portable computer providedwith a wireless interface card or other wireless interface facility,personal data assistant (PDA) provided with wireless communicationcapabilities, or any combinations of these or the like. The mobiledevice may communicate via an appropriate radio interface arrangement ofthe mobile device. The interface arrangement may be provided for exampleby means of a radio part 7 and associated antenna arrangement. Theantenna arrangement may be arranged internally or externally to theapparatus 8.

The apparatus 8 may be provided with at least one data processing entity3 and at least one memory or data storage entity 7 for use in tasks itis designed to perform. The data processor 3 and memory 7 may beprovided on an appropriate circuit board 9 and/or in chipsets.

The user may control the operation of the apparatus 8 by means of asuitable user interface such as key pad 1, voice commands, touchsensitive screen or pad, combinations thereof or the like. A display 5,a speaker and a microphone may also be provided. Furthermore, theapparatus 8 may comprise appropriate connectors (either wired orwireless) to other devices and/or for connecting external accessories,for example hands-free equipment, thereto.

As can be seen with respect to FIG. 2, the apparatus 8 may be configuredto communicate with at least one of a number of access nodes 2, 4, 6,for example when it is located in the coverage area 101 of a firstaccess node 2 the apparatus is configured to be able to communicate tothe first access node 2, when in the coverage area 103 of a second node4 the apparatus may be able to communicate with the second access node4, and when in the coverage area 105 of the third access node 6 theapparatus may be able to communicate with the third access node 6.

FIG. 3 shows an example of the first access node, which in thisembodiment of the invention is represented by an evolved node B (eNB)according to an embodiment of the present invention. The eNB 2 comprisesa radio frequency antenna 301 configured to receive and transmit radiofrequency signals, radio frequency interface circuitry 303 configured tointerface the radio frequency signals received and transmitted by theantenna 301 and the data processor 167. The radio frequency interfacecircuitry may also be known as a transceiver. The access node (evolvednode B) 2 may also comprise a data processor configured to processsignals from the radio frequency interface circuitry 303, control theradio frequency interface circuitry 303 to generate suitable RF signalsto communicate information to the apparatus 8 via the wirelesscommunications link. The access node further comprises a memory 307 forstoring data, parameters and instructions for use by the data processor305.

It would be appreciated that both the apparatus 8 and access node 2shown in FIGS. 2 and 3 respectively and described above may comprisefurther elements which are not directly involved with the embodiments ofthe invention described hereafter.

Although the following describes embodiments of the invention usingevolved node B (eNB) apparatus operating within an EUTRAN, furtherembodiments of the invention may be performed in any base station, nodeB and evolved node B suitable for communicating with a user equipmentcapable of communication in that access network, and further comprisingdata processing and storage capacity suitable for carrying theoperations as described below.

According to an embodiment of the invention, a radio network of the kindillustrated in FIG. 1 (including the plurality of cells served by therespective access nodes (eNodeBs) 2, 4, 6) is designed to supportcarrier aggregation of N non-contiguous different frequency bands asshown in FIG. 4. The frequency bands may have different or samebandwidths, and arbitrary centre frequencies. An example configurationcould be N=2, in other word two separate channels, where a first channelhas a 10 MHz bandwidth below 1 GHz and a second channel with a 20 MHzbandwidth above 20 MHz. In this example the access node 2 data processor305 may dynamically schedule the apparatus 8 within the coverage area101 (in other words under its control) to use these N=2 frequency bands.

In the case of an SC-FDMA uplink transmission from the user equipment(UE) 8 to the eNodeB 2, the eNode-B 2 data processor 305 may select agroup of orthogonal sub-carriers in one of the two frequency bands forthe transmission of data from the UE 8 to the e-Node B 2, and inform theUE 2 accordingly by means of a physical down-link control channel(PDCCH). The division of a section of a frequency band 10 into alocalised group 12 of orthogonal sub-carriers is illustrated in FIG. 5.

The SC-FDMA transmission includes (i) creating a representation of aseries of data symbols (which data symbols are themselves created fromthe original data bits) in the time-domain; (ii) converting thetime-domain representation into a frequency-domain representation usinga discrete Fourier transform (DFT) to create a group of DFT bins at aseries of orthogonal frequencies, with each bin representing onesub-carrier with amplitude and phase held constant for the transmissionsymbol time; and (iii) then applying an Inverse Fast FourierTransformation (IFFT) function to create a series of samples that areused to generate a multi-carrier signal. This last step (iii) is themathematical equivalent of generating each sub-carrier signal by aseparate transmission chain hardware block, and summing the output ofsuch blocks for sending the resulting signal over the wirelessinterface. At the receiving end (eNodeB), the received signal is firstdemodulated and amplified, and then treated by a fast Fouriertransformation function (FFT) which converts the time signal back intothe frequency domain. The resulting amplitude diagram is fed to anInverse Fast Fourier Transformation (IFFT) function, and the resultingtime domain signal is then fed to a single detector block whichrecreates the original bits.

The transmission protocol may further specify that at any onetime-instant the UE 2 can only be scheduled for a transmission in asingle one of the N=2 frequency bands. According to one variation, theuplink (UL) data for transmission from the UE 2 to the eNode B 8 isdivided up and allocated to different ones of the N=2 non-contiguousfrequency bands before channel coding. The UE 2 decodes PDCCH frommultiple downlink (DL) subbands to determine which respective group oforthogonal sub-carriers to use in each of the N=2 frequency bands andtransmits the uplink (UL) data accordingly. The transmission of the ULdata allocated to one of the N=2 frequency bands is independent of thesimultaneous transmission of the UL data allocated to the other of theN=2 frequency bands; for example, the two groups of data are subject torespective discrete Fourier transform (DFT) operations. Hybrid automaticrepeat request (HARQ) operations (i.e. the provision of acknowledgement(ACK) or non-acknowledgment (NACK) feedback messages to the UE2) arecarried out on a frequency-band specific basis.

With respect to FIG. 6 the operation of controlling the transmissionpower of the SC-FDMA uplink transmissions is further described below.

The apparatus 8 data processor firstly determines one of the N=2frequency bands as being a primary band. The primary band may bespecific for each cell or access node (eNB) 2, or specific to theapparatus (UE) 8. In a first embodiment of the invention the access nodetransmits the number or the indicator of the primary band using theRadio Resource Control (RRC) signalling information. However any othersuitable signalling pathway may be used to transmit this information tothe apparatus from the access network. In some embodiments of theinvention the apparatus 8 determines the primary band and indicates thisinformation to the access node as part of an uplink data signal. Theoperation of determining the primary band is shown in FIG. 6 by step601.

The apparatus 8 having determined the primary band, measures only theintegral path loss between the apparatus 8 and the serving access node 8for the primary band.

The integral path loss may be determined or measured for the primaryband (PL_primary) between the apparatus 8 and the access node 2 by theapparatus 8. This may be achieved for example by the apparatus 8monitoring a reference signal which has a known or predetermined signalstrength transmitted from the access node 2. The difference between thereceived reference signal strength and the reference signal strengthcalculated at the apparatus data processor 3 thus may define a path lossin the down link. The reference signal may not in embodiments of theinvention have the same frequency as the primary band or be transmittedat the same time as the primary band is transmitted. However where thereference signal is transmitted either at a similar time or frequency tothe primary band it is understood that the path loss for the referencesignal from the access node 2 to the apparatus 8 will be a good estimateof the path loss for the primary band from the apparatus to the accessnode.

In other embodiments of the invention the primary integral path loss(PL_primary) may be determined or measured within the access node 2 dataprocessor 305 from a reference signal being transmitted from theapparatus 8 to the access node 2. The access node 2 data processor maythen control the radio frequency interface circuitry to 303 to transmitthe integral path loss back to the apparatus.

The operation of determining the primary band integral path loss isshown in FIG. 6 by step 603.

The apparatus 8 data processor 3 furthermore determines the path lossband compensation factors for the remaining frequency bands (PL(n)).

In embodiments the path loss band compensation factors may be passed tothe apparatus from the access node 2.

The access node 2 memory 307 may for example store a look up table ofthe expected path loss differences between frequency bands used by theaccess node 2. The look up table or data is read by the processor 305and then passed to the apparatus 8 via the wireless link using the RRC.

These expected path loss differences may be difference values measuredor determined based on the environment within which the access node 2operates within and the coverage area 101 of the access node 2. As suchthese difference values may be determined accurately during the radionetwork planning phase given the large amount of detailed theoreticalfrequency dependent path loss models and the published propagationmeasurements in the public literature.

The access node 2 processor 305 may in some embodiments of the inventiondetermine the path loss difference PL(n) using approximations of thepath loss models. In other embodiments of the invention the access node2 may monitoring ‘centrally’ the difference in signal strength betweenvarious bands and use these monitored differences to determine the pathloss difference factors.

The determination of the path loss difference values (the path loss bandcompensation factor) is shown in FIG. 6 by step 605.

The apparatus 8 data processor may further determine the path losscompensation factor α(n) by receiving the required values from theaccess node 2. The path loss compensation factor α(n) is a banddependent version of the path loss compensation factor known in the artand may be determined as a 3 bit cell and band specific parameter andprovided by higher access layers.

The determination of the band dependent path loss compensation factorα(n) is shown in FIG. 6 by step 607.

The apparatus 8 data processor may further determine the band dependentparameter P_(o) _(—) _(PUSCH)(n) (for the uplink shared channel − andP_(o) _(—) _(PUCCH)(n) for the uplink control channel) by receiving therequired values from the access node 2. The parameter is a banddependent version of the parameter used in the determination of theuplink power in the art and may be composed of the sum of a 8-bit cellspecific nominal component signalled from higher access layers and anapparatus specific component.

The determination of the band dependent band dependent parameter P_(o)_(—) _(PUSCH)(n) is shown in FIG. 6 by step 609.

The apparatus 8 data processor may then determine the transmission powerfor an uplink SC-FDMA transmission on a physical uplink shared channel(PUSCH) in a frequency band other than the primary band is controlledaccording to the following formula. This formula is a development of aformula specified in 3GPP TS 36.213 for a fractional path losscompensation method.P _(PUSCH)(i)=min{P _(MAX),10 log₁₀(M _(PUSCH)(i))+P _(o) _(—)_(PUSCH)(j,n)+α(n)·(PL_primary+PL(n)) Δ_(TF)(TF(i))+f(i)}[dBm]where,

-   -   P_(MAX) is the maximum allowed power that depends on the UE        power class    -   M_(PUSCH)(i) is the size of the PUSCH resource assignment        expressed in number of resource blocks valid for subframe i.    -   P_(o) _(—) _(PUSCH)(j,n) is the parameter discussed above and        composed of the sum of a 8-bit cell specific nominal component        P_(O) _(—) _(NOMINAL) _(—) _(PUSCH) (j) signalled from higher        layers for j=0 and 1 in the range of [−126,24] dBm with 1 dB        resolution and a 4-bit UE specific component P_(O) _(—)        _(PUSCH) (J) configured by RRC for j=0 and 1 in the range of        [−8, 7] dB with 1 dB resolution. For PUSCH (re)transmissions        corresponding to a configured scheduling grant then and for        PUSCH (re)transmissions corresponding to a received PDCCH with        DCI format 0 associated with a new packet transmission then j=1.        This Po parameter is configured independently for each of the N        frequency bands.    -   α(n)ε{0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1} is as discussed above        a 3-bit cell specific parameter provided by higher layers. This        parameter is also configured independently for each of the N        frequency bands.    -   PL_primary is as discussed above the downlink pathloss estimate        for the primary frequency band, which estimate is based on        measurements made at the UE    -   PL(n) is as discussed above a parameter expressing the expected        path loss between the primary frequency band (denoted        PL_primary) and the frequency band #n for which the        transmission(s) are scheduled. The value of PL(n) is signalled        from the eNode-B to the UE.    -   Δ_(TF)(TF(i))=10 log₁₀(2^(MPR·) ^(S) −1) for K_(S)=1.25 and 0        for K_(S)=0 where K_(S) is a cell specific parameter given by        RRC        -   TF(i) is the PUSCH transport format valid for subframe i        -   MPR=modulation×coding rate=N_(INFO)/N_(RE) where N_(INFO)            are the number of information bits and N_(RE) is the number            of resource elements determined from TF(i) and M_(PUSCH)(i)            for subframe i    -   δ_(PUSCH) is a TIE specific correction value, also referred to        as a TPC command and is included in PDCCH with DCI format 0 or        jointly coded with other TPC commands in PDCCH with DCI format        3/3A. The current PUSCH power control adjustment state is given        by f(i) which is defined by:        -   f(i)=f(i−1)+δ_(PUSCH)(i−K_(PUSCH)) if f(*) represents            accumulation            -   where f(0)=0 and K_(PUSCH)=4            -   The UE attempts to decode a PDCCH of DCI format 0 and a                PDCCH of DCI format 3/3A in every subframe except when                in DRX            -   δ_(PUSCH)=0 dB for a subframe where no TPC command is                decoded or where DRX occurs.            -   The δ_(PUSCH) dB accumulated values signalled on PDCCH                with DCI format 0 are [−1, 0, 1, 3].            -   The α_(PUSCH) dB accumulated values signalled on PDCCH                with DCI format 3/3A are one of [−1, 1] or [−1, 0, 1, 3]                as semi-statically configured by higher layers.            -   If UE has reached maximum power, positive TPC commands                are not accumulated            -   If UE has reached minimum power, negative TPC commands                shall not be accumulated            -   UE shall reset accumulation                -   at cell-change                -   when entering/leaving RRC active state                -   when an absolute TPC command is received                -   when P_(O) _(—) _(UE) _(—) _(PUSCH)(j) is received                -   when the UE (re)synchronizes        -   f(i)=δ(i−K_(PUSCH)) if f(*) represents current absolute            value            -   where δ_(PUSCH)(i−K_(PUSCH)) was signalled on PDCCH with                DCI format 0 on subframe i−K_(PUSCH)            -   where K_(PUSCH)=4            -   The δ_(PUSCH) dB absolute values signalled on PDCCH with                DCI format 0 are [−4,−1, 1, 4].            -   f(i)=f(i−1) for a subframe where no PDCCH with DCI                format 0 is decoded or where DRX occurs.        -   f(*) type (accumulation or current absolute) is a UE            specific parameter that is given by RRC.

Where respective groups of data are allocated for simultaneous SC-FDMAtransmissions from the same UE 2 in respective different ones of the Nfrequency bands, the transmission power for each of the frequency bandsis controlled as described above. For a transmission in the frequencyband designated as the primary frequency band, PL(n) is, for course, setto zero. Controlling the transmission power independently for each ofthe N-frequency bands can have the advantage of reducing peak-to-averagepower ratio (PAPR).

In another embodiment, a similar power control scheme is applied totransmissions on the uplink control channel (PUCCH), i.e. the path losscompensation factor and Po_pucch are also specified separately for eachfrequency band, and transmission power is also determined based on anestimate of the path loss difference between the primary frequency bandand the frequency band in which the PUCCH transmission is to be made.

The above-described power control technique makes it possible toefficiently control the power of transmissions in any one of a pluralityof frequency bands, without the UE 2 having to explicitly measure theintegral path loss for each and every one of the plurality of frequencybands (which would typically involve receiving signals from on each andevery one of the plurality of frequency bands). This is particularlysignificant for non-contiguous bands with relative large frequencyseparation, where the integral path loss is likely to be significantlydifferent for each band. The latter is the case due to the frequencydependent radio propagation path loss (i.e. higher path loss for higherfrequencies), and due to potential differences in eNode-B and UE antennagains for the different frequency bands.

Also, specifying independent parameters Po and α for each of theplurality of frequency bands serves to facilitate effective powercontrol even in the case of non-contiguous frequency bands withrelatively large frequency separation, where the path loss distributionis likely to be different for each band.

The above-described technique is considered to be of particular interestin, for example, the development of LTE-A (Long TermEvolution-Advanced).

Appropriately adapted computer program code product may be used forimplementing the above-described functions of the UE 2 and the eNodeB 8.The program code product for providing the operation may be stored onand provided by means of a carrier medium such as a carrier disc, cardor tape. Another possibility is to download the program code product viaa data network.

The applicant draws attention to the fact that the present invention mayinclude any feature or combination of features disclosed herein eitherimplicitly or explicitly or any generalisation thereof, withoutlimitation to the scope of any definitions set out above.

The above described operations may require data processing in thevarious entities. The data processing may be provided by means of one ormore data processors. Similarly various entities described in the aboveembodiments may be implemented within a single or a plurality of dataprocessing entities and/or data processors. Appropriately adaptedcomputer program code product may be used for implementing theembodiments, when loaded to a computer. The program code product forproviding the operation may be stored on and provided by means of acarrier medium such as a carrier disc, card or tape. A possibility is todownload the program code product via a data network. Implementation maybe provided with appropriate software in a server.

For example the embodiments of the invention may be implemented as achipset, in other words a series of integrated circuits communicatingamong each other. The chipset may comprise microprocessors arranged torun code, application specific integrated circuits (ASICs), orprogrammable digital signal processors for performing the operationsdescribed above.

Embodiments of the inventions may be practiced in various componentssuch as integrated circuit modules. The design of integrated circuits isby and large a highly automated process. Complex and powerful softwaretools are available for converting a logic level design into asemiconductor circuit design ready to be etched and formed on asemiconductor substrate.

Programs, such as those provided by Synopsys, Inc. of Mountain View,Calif. and Cadence Design, of San Jose, Calif. automatically routeconductors and locate components on a semiconductor chip using wellestablished rules of design as well as libraries of pre-stored designmodules. Once the design for a semiconductor circuit has been completed,the resultant design, in a standardized electronic format (e.g., Opus,GDSII, or the like) may be transmitted to a semiconductor fabricationfacility or “fab” for fabrication.

Also, in view of the foregoing description it will be evident to aperson skilled in the art that various modifications of the describedembodiments may be made within the scope of the invention.

The invention claimed is:
 1. A method, comprising: making one or more determinations at a mobile device of path loss for a transmission between said mobile device and a base station in a first frequency band of a plurality of frequency bands in which the mobile device is configured to make transmissions to said base station; receiving at said mobile device path loss estimate information specifying an estimate of the relationship between said path loss for a transmission between said mobile device and said base station in said first frequency band, and path loss for a transmission between said mobile device and said base station in a second frequency band of said plurality of frequency bands; and determining a transmission power for at least one transmission to said base station in said second frequency band on the basis of at least said one or more determinations and said path loss estimate information.
 2. A method according to claim 1, wherein said path loss estimate information is received from said base station as part of radio resource control signalling, or part of cell-specific system information.
 3. A method according to claim 1, wherein the base station is part of a network of base stations, and said first frequency band is specified to be the same for any link between said mobile device and any of said network of base stations.
 4. A method according to claim 1, wherein the at least one transmission is a multi-carrier transmission at a series of orthogonal frequencies within said second frequency band.
 5. A non-transitory computer readable medium comprising program code which when loaded into a computer controls the computer to perform a method according to claim
 1. 6. A method according to claim 1, further comprising determining a band-dependent parameter composed of the sum of a cell specific nominal component signaled from higher access layers and a mobile device specific component.
 7. A method according to claim 6, further comprising determining a transmission power for at least one transmission to said base station in said second frequency band on the basis of at least said one or more determinations of path loss, said band-dependent parameter and said path loss estimate information.
 8. A method comprising: sending to a mobile device path loss estimate information specifying an estimate of the relationship between path loss for a transmission between said mobile device and a base station in a first frequency band of a plurality of frequency bands in which said mobile device is configured to make transmissions to said base station, and path loss for a transmission between said mobile device and said base station in a second frequency band of said plurality of frequency bands.
 9. A method according to claim 8, wherein said path loss estimate information is sent to said mobile device as part of radio resource control signalling, or part of cell-specific system information.
 10. A method according to claim 8, wherein the first frequency band is specified to be the same for any link between any mobile device and said base station.
 11. A non-transitory computer readable medium comprising program code which when loaded into a computer controls the computer to perform a method according to claim
 8. 12. An apparatus, comprising: one or more processors; and one or more memories including computer program code, the one or more memories and the computer program code configured, with the one or more processors, to cause the apparatus to perform at least the following: make one or more determinations at a mobile device of path loss for a transmission between said mobile device and a base station in a first frequency band of a plurality of frequency bands in which the mobile device is configured to make transmissions to said base station; receive at said mobile device path loss estimate information specifying an estimate of the relationship between said path loss for a transmission between said mobile device and said base station in said first frequency band, and path loss for a transmission between said mobile device and said base station in a second frequency band of said plurality of frequency bands; and determine a transmission power for at least one transmission to said base station in said second frequency band on the basis of at least said one or more determinations and said path loss estimate information.
 13. An apparatus according to claim 12, which is configured to receive said path loss estimate information from said base station as part of radio resource control signalling, or part of cell-specific system information.
 14. An apparatus according to claim 12, wherein the base station is part of a network of base stations, and said first frequency band is specified to be the same for any link between said mobile device and any of said network of base stations.
 15. An apparatus according to claim 12, wherein the at least one transmission is a multi-carrier transmission at a series of orthogonal frequencies within said second frequency band.
 16. An apparatus, comprising: one or more processors; and one or more memories including computer program code, the one or more memories and the computer program code configured, with the one or more processors, to cause the apparatus to perform at least the following: send to a mobile device path loss estimate information specifying an estimate of the relationship between path loss for a transmission between said mobile device and a base station in a first frequency band of a plurality of frequency bands in which said mobile device is configured to make transmissions to said base station, and path loss for a transmission between said mobile device and said base station in a second frequency band of said plurality of frequency bands.
 17. An apparatus according to claim 16, wherein said path loss estimate information is sent to said base station mobile device as part of radio resource control signalling, or part of cell-specific system information.
 18. An apparatus according to claim 16, wherein the first frequency band is specified to be the same for any link between any mobile device and said base station. 